1. Field of the Invention
The present invention relates to in general an infrared traffic sensor, and in particular a system and method for generating feature curves to derive empirical information for determining traffic patterns.
2. Related Art
Traffic sensing systems are used to collect traffic data in order to measure the flow of traffic on a roadway or thoroughfare. Typically, equipment of the traffic sensing system is placed in close proximity to the roadway or thoroughfare to physically track vehicles traveling on the roadway or thoroughfare.
One traffic sensing system is a direct contact counting device which includes one or more pneumatic tubes placed across the roadway pavement. Each vehicles traveling on the roadway crosses over the pneumatic tube to actuate a switch that operates a counting device, thereby counting every vehicle that crosses over the tube. Permanent direct counting devices can be actually embedded in the pavement during construction of the roadway. These devices utilize wire loops instead of pneumatic tubes to sense vehicles through magnetic induction.
However, direct contact counting devices are limited in their use. For example, they are not practical for accurately calculating the speed of vehicles or the speed flow of traffic. In addition, pneumatic tube direct contact counting devices are susceptible to miscounts due to multi-axile vehicles, misalignment of the tubes, or proper upkeep. Also, permanent wire loop systems are not practical because they cannot be used for temporary purposes, have accuracy problems similar to the pneumatic tube direct contact counting devices, and are very expensive and usually impractical to install after the roadway is completed.
Other types of traffic sensing systems include camera monitoring systems. These systems typically include a camera placed over a thoroughfare or roadway and collect data in the form of tracked conditions on the roadway. The tracked conditions are sent to a processor which processes the data to calculate characteristics of the traffic conditions.
However, these system are limited because they do not accurately determine the number of vehicles, the speed of the vehicles, and the classification of the vehicles. In addition, many of these systems do not contain signal processing algorithms that can derive empirical information for determining traffic patterns and measure lane density accurately.
Therefore, what is needed is an infrared traffic sensor for generating accurate feature curves to determine the number of vehicles, the speed of the vehicles, and the classification of the vehicles. What is also needed is a traffic sensor and a signal processing algorithm that can derive empirical information for determining traffic patterns. What is further needed is a traffic sensor that can measure lane density accurately.
Whatever the merits of the prior techniques and methods, they do not achieve the benefits of the present invention.